The present invention relates to a gas distributor apparatus for fuel-injection systems of internal combustion engines for supplying gas to at least two devices for injecting a fuel-gas mixture in accordance with the species defined in the main claim.
It is already disclosed by the European Patent No. 0 357 498 to arrange devices for injecting a fuel-gas mixture in receiving bores of an intake manifold of the internal combustion engine. A gas feed duct, which communicates with a gas line in the form of a hose running outside of the intake manifold, opens through into each of the receiving bores. The disadvantage of supplying gas to devices in this manner for injecting a fuel-gas mixture is that a separate gas line that runs outside of the intake manifold is required for each device. Because of the complicated design and costly assembly, this leads to high manufacturing costs for the fuel-injection system. A further disadvantage is entailed by the complex design of the intake manifold. Moreover, when the intake manifold heats up, the gas is also heated, so that the result is a decrease in the volume flowing through.
Furthermore the German Patent Application No. 42 05 709 already discloses a gas distributor for fuel-injection systems for mutually supplying gas to a plurality of devices, e.g., to fuel injectors for injecting a fuel-gas mixture. The configuration of the gas distributor is such that receiving bores and gas supply lines joining said bores are provided in conformance with the number of fuel injectors. The receptacles having the receiving bores for the fuel injectors are realized as gas-containing bodies, which radially surround the downstream ends of the fuel injectors. In this case, one does without a costly supplying of the fuel injectors with gas for injecting a fuel-gas mixture by means of individual gas lines in the form of hoses or pipe conduits running separately to each fuel injector.
However, the structural refinement of the gas distributor requires that the individual fuel injectors always be supplied with gas as directly coupled injectors, since the gas-supply lines run from receptacle to receptacle. Thus, for example, the last fuel injector to be installed in the gas distributor is supplied with gas that has already flowed through all the other receiving bores. In addition, very narrow installation tolerances must be observed to ensure a precise assembly of the relatively rigid gas distributor.
In contrast, the advantage of the gas distributor apparatus according to the present invention is that a simple, inexpensive, reliable, and easily manipulable shared supplying of a plurality of devices with gas, e.g., of fuel injectors for injecting a fuel-gas mixture is guaranteed. The gas distributor apparatus constitutes a very compact unit that is able to be assembled and disassembled on the devices very simply. The gas distributor apparatus in accordance with the present invention makes it possible to avoid a multiplicity of separately running gas lines, since a plurality of devices, e.g., arranged in series, are supplied at the same time by this one gas distributor apparatus. In addition, the gas distributor apparatus advantageously has a gas-supply line with an inner supply orifice, from which branched-off ports are introduced in connecting pieces, said branched-off ports conforming in number to the number of devices to be supplied with gas and said branched-off ports communicating directly with gas-containing bodies of the devices.
Thus, the gas is simultaneously made available for all devices in the supply orifice of the gas-supply line and then flows via each connecting piece that is formed in one piece with the gas-supply line to a device. Without circumflowing all the devices, gas is supplied separately to each device using the only one compact gas distributor apparatus, so that each device is supplied with a comparatively cool gas, through which means a better charging is achieved. It is especially advantageous that the gas-distributor device is able to be assembled and disassembled very simply, as there is no need whatsoever to change the position of the devices.
It is especially advantageous for the gas distributor apparatus of the present invention to be manufactured in one piece out of the gas-supply line that runs along a longitudinal axis of the gas distributor, with the connecting pieces constructed to correspond to the number of devices, together with an electrical socket connector (contact) strip, which is used for the electrical contacting of the devices, and with a connecting element that joins the gas-supply line to the electrical socket connector strip. The gas distributor apparatus forms an especially compact assembly when the gas-supply line, the electrical socket connector strip, and the connecting element have the same axial extent along the longitudinal axis of the gas distributor. Thus, this combined gas distributor apparatus manufactured, e.g., from plastic fulfills two functions, namely supplying the devices with gas for fuel containment and simultaneously providing for the electrical contacting of the devices.
To be able to establish a simple and rapid connection between the gas-containing bodies surrounding the devices for injecting a fuel-gas mixture and the gas distributor apparatus, it is beneficial for the gas-intake ducts that project out of the gas-containing bodies, as well as the connecting pieces of the gas-distributor device to have functional elements which cooperate with snap-in, plug-in, or snap-fit connections.